Here's a rundown of several key claims made during the hearing, and our reporting on the issues and numbers referenced by officials.

Mayors of four of the largest cities in the U.S. appeared before lawmakers in the U.S. House of Representatives on Wednesday to defend their so-called "sanctuary city" laws, which restrict local officials in helping enforce federal immigration regulations.

Johnson and the other mayors defended their immigration policies, saying they have an obligation to protect everyone living in their cities, regardless of their immigration status.

Mayor Johnson and three other big-city mayors testified before the U.S. House Oversight Committee on their sanctuary city policies Wednesday. Political Reporter Chris Tye reports from Washington.

Johnson had a gameplan of what he wanted to stress to congressional Republicans in his testimony. In fact, he made his point at least 18 times.